| /* |
| * Copyright (c) 2005-2014 Lev Walkin <vlm@lionet.info>. |
| * All rights reserved. |
| * Redistribution and modifications are permitted subject to BSD license. |
| */ |
| #include <asn_system.h> |
| #include <asn_internal.h> |
| #include <per_support.h> |
| |
| /* |
| * X.691-201508 #10.9 General rules for encoding a length determinant. |
| * Get the optionally constrained length "n" from the stream. |
| */ |
| ssize_t |
| uper_get_length(asn_per_data_t *pd, int ebits, int *repeat) { |
| ssize_t value; |
| |
| *repeat = 0; |
| |
| /* #11.9.4.1 Encoding if constrained (according to effective bits) */ |
| if(ebits >= 0 && ebits <= 16) { |
| return per_get_few_bits(pd, ebits); |
| } |
| |
| value = per_get_few_bits(pd, 8); |
| if((value & 0x80) == 0) { /* #11.9.3.6 */ |
| return (value & 0x7F); |
| } else if((value & 0x40) == 0) { /* #11.9.3.7 */ |
| /* bit 8 ... set to 1 and bit 7 ... set to zero */ |
| value = ((value & 0x3f) << 8) | per_get_few_bits(pd, 8); |
| return value; /* potential -1 from per_get_few_bits passes through. */ |
| } else if(value < 0) { |
| return -1; |
| } |
| value &= 0x3f; /* this is "m" from X.691, #11.9.3.8 */ |
| if(value < 1 || value > 4) { |
| return -1; /* Prohibited by #11.9.3.8 */ |
| } |
| *repeat = 1; |
| return (16384 * value); |
| } |
| |
| /* |
| * Get the normally small length "n". |
| * This procedure used to decode length of extensions bit-maps |
| * for SET and SEQUENCE types. |
| */ |
| ssize_t |
| uper_get_nslength(asn_per_data_t *pd) { |
| ssize_t length; |
| |
| ASN_DEBUG("Getting normally small length"); |
| |
| if(per_get_few_bits(pd, 1) == 0) { |
| length = per_get_few_bits(pd, 6) + 1; |
| if(length <= 0) return -1; |
| ASN_DEBUG("l=%d", (int)length); |
| return length; |
| } else { |
| int repeat; |
| length = uper_get_length(pd, -1, &repeat); |
| if(length >= 0 && !repeat) return length; |
| return -1; /* Error, or do not support >16K extensions */ |
| } |
| } |
| |
| /* |
| * Get the normally small non-negative whole number. |
| * X.691, #10.6 |
| */ |
| ssize_t |
| uper_get_nsnnwn(asn_per_data_t *pd) { |
| ssize_t value; |
| |
| value = per_get_few_bits(pd, 7); |
| if(value & 64) { /* implicit (value < 0) */ |
| value &= 63; |
| value <<= 2; |
| value |= per_get_few_bits(pd, 2); |
| if(value & 128) /* implicit (value < 0) */ |
| return -1; |
| if(value == 0) |
| return 0; |
| if(value >= 3) |
| return -1; |
| value = per_get_few_bits(pd, 8 * value); |
| return value; |
| } |
| |
| return value; |
| } |
| |
| /* |
| * X.691-11/2008, #11.6 |
| * Encoding of a normally small non-negative whole number |
| */ |
| int |
| uper_put_nsnnwn(asn_per_outp_t *po, int n) { |
| int bytes; |
| |
| if(n <= 63) { |
| if(n < 0) return -1; |
| return per_put_few_bits(po, n, 7); |
| } |
| if(n < 256) |
| bytes = 1; |
| else if(n < 65536) |
| bytes = 2; |
| else if(n < 256 * 65536) |
| bytes = 3; |
| else |
| return -1; /* This is not a "normally small" value */ |
| if(per_put_few_bits(po, bytes, 8)) |
| return -1; |
| |
| return per_put_few_bits(po, n, 8 * bytes); |
| } |
| |
| |
| /* X.691-2008/11, #11.5.6 -> #11.3 */ |
| int uper_get_constrained_whole_number(asn_per_data_t *pd, unsigned long *out_value, int nbits) { |
| unsigned long lhalf; /* Lower half of the number*/ |
| long half; |
| |
| if(nbits <= 31) { |
| half = per_get_few_bits(pd, nbits); |
| if(half < 0) return -1; |
| *out_value = half; |
| return 0; |
| } |
| |
| if((size_t)nbits > 8 * sizeof(*out_value)) |
| return -1; /* RANGE */ |
| |
| half = per_get_few_bits(pd, 31); |
| if(half < 0) return -1; |
| |
| if(uper_get_constrained_whole_number(pd, &lhalf, nbits - 31)) |
| return -1; |
| |
| *out_value = ((unsigned long)half << (nbits - 31)) | lhalf; |
| return 0; |
| } |
| |
| |
| /* X.691-2008/11, #11.5.6 -> #11.3 */ |
| int uper_put_constrained_whole_number_s(asn_per_outp_t *po, long v, int nbits) { |
| /* |
| * Assume signed number can be safely coerced into |
| * unsigned of the same range. |
| * The following testing code will likely be optimized out |
| * by compiler if it is true. |
| */ |
| unsigned long uvalue1 = ULONG_MAX; |
| long svalue = uvalue1; |
| unsigned long uvalue2 = svalue; |
| assert(uvalue1 == uvalue2); |
| return uper_put_constrained_whole_number_u(po, v, nbits); |
| } |
| |
| int uper_put_constrained_whole_number_u(asn_per_outp_t *po, unsigned long v, int nbits) { |
| if(nbits <= 31) { |
| return per_put_few_bits(po, v, nbits); |
| } else { |
| /* Put higher portion first, followed by lower 31-bit */ |
| if(uper_put_constrained_whole_number_u(po, v >> 31, nbits - 31)) |
| return -1; |
| return per_put_few_bits(po, v, 31); |
| } |
| } |
| |
| /* |
| * Put the length "n" (or part of it) into the stream. |
| */ |
| ssize_t |
| uper_put_length(asn_per_outp_t *po, size_t length) { |
| |
| if(length <= 127) /* #10.9.3.6 */ |
| return per_put_few_bits(po, length, 8) |
| ? -1 : (ssize_t)length; |
| else if(length < 16384) /* #10.9.3.7 */ |
| return per_put_few_bits(po, length|0x8000, 16) |
| ? -1 : (ssize_t)length; |
| |
| length >>= 14; |
| if(length > 4) length = 4; |
| |
| return per_put_few_bits(po, 0xC0 | length, 8) |
| ? -1 : (ssize_t)(length << 14); |
| } |
| |
| |
| /* |
| * Put the normally small length "n" into the stream. |
| * This procedure used to encode length of extensions bit-maps |
| * for SET and SEQUENCE types. |
| */ |
| int |
| uper_put_nslength(asn_per_outp_t *po, size_t length) { |
| |
| if(length <= 64) { |
| /* #10.9.3.4 */ |
| if(length == 0) return -1; |
| return per_put_few_bits(po, length-1, 7) ? -1 : 0; |
| } else { |
| if(uper_put_length(po, length) != (ssize_t)length) { |
| /* This might happen in case of >16K extensions */ |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |